Aaron Ramsey's late winner for Arsenal against Marseilles in France last night put Arsène Wenger's team on course for qualification for the knockout round of the Champions League and was more evidence, Wenger said, that his team are heading in the right direction.

Chelsea are also top of their group with seven points after Fernando Torres scored twice in a comprehensive 5-0 defeat of Belgian champions Genk, the biggest margin of victory the club have ever recorded in the Champions League. It was also Torres' first goals in the competition for more than two years.

Arsenal are a point clear of Marseilles in Group F, who they beat with a late and largely undeserved winner, but that did not trouble Wenger who said that his team had "been unlucky in this competition in the past".

Wenger paid tribute to Ramsey who scored the winner in injury-time at the end of the game. "It was a great finish," he said. "When you see Aaron in front of goal you know you have a good chance to score. He is becoming a real goalscorer. He has been injured for a year and I am conscious of how much [the currently injured Jack] Wilshere played last year. I try to be a bit more cautious when I can about playing him."

Wenger added: "We left it very late. We had a difficult start with Marseilles pressing us well and we didn't find our fluency. We had experience in midfield, we didn't make stupid mistakes and we took over in the second half when Marseilles weren't dangerous. They defended well but in the last 15 minutes we created chances and were rewarded because we kept going and got a very important victory.

"We have made a little step forward but we have to be humble. We are a team who has to continue to grow. This result will help our confidence. If you look back at the last five or six games, you will see only one defeat. We are slowly getting there."

The one worry for Wenger was another injury, to defender Carl Jenkinson who was already understudying Bacary Sagna. "He overstretched his knee," said Wenger. "We have to check that tomorrow.

"Was it lucky? Three substitutes combined for the goal, that makes me lucky, but we haven't always been lucky in this competition. We lost a goal late in Dortmund [in this season's first group game] and we lost the [2006] Champions League final in the final minutes with 10 men."

Didier Deschamps the Marseilles manager, said: "It's a cruel disappointment. When you lose a game like that in injury time it's even harder to take. I was angry Ramsey was alone at the back post. Ramsey had all the time he needed to control the ball and score. I asked them to be cautious so I was very angry."

Andre Villas-Boas said that his options in attack were among the best in the world after he left Didier Drogba out the squad last night. He said: "Our goals have been spread out in various ways in our squad. The strikers are nearer to goal and get in good positions – Fernando did that very well – but we look at the collective performance.

"I'm pretty pleased with the way the team played. It would have been a long period off [if Torres hadn't played because of his suspension in the Premier League], though we are able to choose from the best up front. The choice fell with Fernando and he responded pretty well, as have all the strikers who have been used."

Torres is out of the game against Queen's Park Rangers on Sunday when he serves the last game of his ban for a red card against Swansea City. Villas-Boas said that he believed the game against Bayer Leverkusen on 23 November would be decisive in whether Chelsea finished top of their group and potentially avoided some of the bigger clubs in the seeded draw for the next round.

He said: "This group could become very tight depending on what happens in Leverkusen with Valencia. We just have to try and get three points in Genk. That won't be easy, coming as it does after an Arsenal game. We have to show the right motivation over there.

"The most important months for us will be the last three of the season, when you finally collide or not with trophies. For now, we're just aiming at our objectives. We want the best results as possible to get qualification through, and keep on track for going as far as we can in the competition."